Regulating system



NOV. 21, 1933- c 5 gfis ET AL 1,936,049

- REGULATING SYSTEM Filed Oct. 3, 1931 l g oer Mao/ling INVENTOR Clqyton D. D/Wers BY Raymond E 0Z5 Patented Nov. 21, l933 ,UNIITE'D STATES l,936,049 REGULATIN G SYSTEM Clayton D. De Men and Raymond E. Olson,

Rochester, N. Y., asslgnors to Taylor Instrument Companies, Rochester, N. Y., a corporation of New York Application October 3, 1931. Serial No; 566,676

-1o Claims.

This invention relates to a regulating system and more particularly to a regulating system adapted to control the uniformity of weight of paper made in a Fourdrinier paper machine.

In the making of paper in a Fourdrinier machine, the weight of the paper is largely determined by regulating the head or pressure of the pulp in the pond where it is supplied through the slice opening to the paper-forming wire screen.

In the past, it has been the practice to regulate this head or pressure at the adjustable slice opening by manually controlling the amount of pulp supplied to the head box. This method of control has not been entirely satisfactory, not only from the fact that it requires the close attention of the operator, but also due to the fact that variations in the speed of the operation of the pump for pumping pulp into the pond? and also variations in the speed of the paper-forming wire screen result in a lack of uniformity in the weight of the finished paper, which can hardly be overcome by any manual adjustment.

In accordance with one feature of the present invention, a novel arrangement is provided for maintaining the proper head of pulp in the pond whereby uniformity of the finished paper results. A further feature of the invention relates to the provision of means responsive to the head of pulp in the pond, for controlling the amount of pulp supplied to the head box of a paper machine.

For a clearer understanding of the invention, reference is made to the drawing wherein 5 designates a pulp stock supply line through which the liquid pulp may be pumped under the control of a regulating motor valve 6, into container 7. In this container there are provided a series of screens (not shown) to segregate the unground pieces of wood while permitting the pulp of proper texture to pass therethru and flow through the outlet 8 into the head box generally designated 9, to form a pond of pulp. This box has a series of baffle plates 10 which, among other purposes, serve to prevent the pulp therein from being greatly disturbed by the incoming flow of fresh pulp from the outlet. On one side of the head box, there is provided an apron board 11 positioned adjacent the breast roll 12 of a Well-known Fourdrinier paper machine. Above and to the left of the apron heard there is an adjustable slice 13 defining a slice opening 16 from the head box adjacent the breast roll. It will be understood that the breast roll 12, together with a similar roll 13 serve to support and continuously rotate a wire screen belt 14 past the apron board. It is well-known in the art that as the wire screen 14 moves past the opening 16 in the pond, the pulp flows over an apron 60 and forms a sheet on this moving screen, and that the thickness of the resulting paper is determined not only by the speed of the wire screen, but also by the size of the slice opening and by the level and consistency of the wood pulp within the head box.

When it is desired to produce paper of uniform weight, it is necessary to make frequent adjustments in the valve controlling the incoming supply of pulp in order to maintain a desired level of pulp in the pond. This need arises from the fact that there are variations in the speed of the power unit used for driving the pump of the incoming pulp supply and variations in the consistency of the pulp stock which delays its flow through the various pipes and fittings.

In the past, these adjustments have all been made manually by an attendant, but such manual control has not permitted the manufacture of paper of the desired uniformity in weight. In order to approach more nearly this desired uniformity, means are provided in accordance with the present invention Which determine the amount of pulp supplied to the head box, in accordance with the speed of the wire screen and/or the pressure of the pulp stock at the slice opening 16 in the head box. For this purpose, there is provided in the head box, a chamber or cylinder 1'! open at its lower end and tightly closed at its upper end except for the openings into the two conduits l8 and 19. The conduit 18 leads through a hand valve 20 to a pipe 21 which is connected to a pressure-fluid source, such as compressed air, while the conduit 19 leads to a capsular structure or diaphragm 22 supported on the fixed bracket 23. On the upper surface of this diaphragm, there rests an adjustable cam 24, nor-,

mally engaging a tappet of the pilot valve gener ally designated 25. This pilot valve is fastened to the free end of an arm or lever 26 pivotally mounted at 27 and under tension of spring 28 tending to move the pilot valve downward. However, the free end of the lever 26 rests on the rocking arm 29, which is pivoted at 30 and which is actuated by a spring to move its left hand end upward. The other end of the arm 29 rests on the rotatable disk 31 attached to a fly ball governor 32, which governor includes rotatable shaft 33 supported in brackets 34. The shaft 33 is driven through bevel gears (not shown) by pulleys and the belt 35 or other suitable means, in

accordance with the speed of the breast roll 12 of the paper machine.

The pilot valve 25 controls the flow of air pressure from the pipe 21 through the conduit 36 to the top of the motor diaphragm valve 6, thereby serving to control its operation.

In the operation of the control apparatus of this invention, compressed air passing through the pipe 21 from the air pressure source, is supplied to the chamber or cylinder 17. The pressure of this air is adjusted by the hand valve 20 until air just begins to bubble from under the edge of the cylinder 1''! at the time when the desired pond level in the head box exists. If, after such adjustment, the height of the pulp in the head box increases or the consistency of the pulp changes, the air instead of bubbling from the cylinder 17 passes through the conduit 19 to actuate diaphragm 22. This diaphragm, through the action of cam 24 bearing on the tappet of pilot valve 25, causes this valve to control the flow of air through the pipe 21, permitting it to pass through the conduit 36 to the top of the motor diaphragm valve 6, thereby causing this valve to close to a point where the proper pond level in the head box is restored. In the event that the level of the pond of pulp in the head box becomes lower than it should be, then more air will escape from the cylinder 17 thereby reducing the pressure in the conduit 19, which causes the diaphragm 22 to contract. This, in turn, closes pilot valve 25 to relieve the pressure in the conduit 36 to the top of the motor diaphragm valve, permitting this valve to open accordingly.

In the foregoing description, it has been assumed that the speed of the wire screen 14 has been uniform. It will now be assumed that the speed of the screen varies. In the event that the speed of the screen increases, the breast roll 12 together with the belt 35 cause the shaft 33 of the fly-ball governor 32 to rotate faster and consequently the rotatable disc 31 on the fly-ball governor will be elevated, thereby rocking the pivoted arm 29 to lower the free end of the pilot valve arm 26, so that under this condition the pilot valve 25 is responsive to a much smaller expansion of the capsular diaphragm 22. However, if the speed of the wire screen 14 slows down, the fly-ball governor 32 rotates more slowly, thereby permitting its disc 31 to be in a lower position and the pivoted arm 29 elevates the free end of the pilot valve arm 26 so that the pilot valve is responsive only to a much greater expansion of diaphragm 22.

From the foregoing it will be observed that the flow of the pulp into the head box is determined by the diaphragm control valve 6 in the stock supply line 5, and this valve is governed both by the height or level of the pond in the head box and also by the speed of the moving screen of the paper machine.

We claim:

1. The method of controlling the thickness of machine-made paper which comprises regulating the flow of pulp to said machine in response to a change in the speed of the machine and in re-- sponse to a change in the pressure of the pulp supplied thereto.

2. The method of controlling the thickness of machine-made paper which comprises compensating for variation in the speed'of said machine 'and/or variation in the pressure of pulp supplied thereto by regulating the amount of pulp supplied to said machine in accordance with said variation.

3. In combination with a Fourdrinier paper machine including a moving screen, a head box provided with a slice opening leading to said screen, a pipe through which pulp is supplied to said head box, and means automatically controlling the pressure of the pulp supplied to said slice opening comprising a valve in said pipe, and mechanism controlling the opening of said valve in accordance with the consistency of the pulp in said box.

4. In combination with a Fourdrinier paper machine including a moving screen, a head box provided with a slice opening leading to said screen, a pipe through which pulp is supplied to said head box, and means automatically controlling the pressure of pulp supplied to said slice opening comprising a valve in said pipe and mechanism controlling the opening of said valve in accordance with the height of the pulp in said box and in accordance with the speed of said moving screen.

5. In combination with a Fourdrinier paper machine including a moving screen, a head box provided with a slice opening leading to said screen, a pipe through which pulp is supplied to said head box, a valve controlling the flow of pulp through said pipe, and means for regulating said valve in accordance with the level and consistency of the pulp in said head box.

6. In combination with a Fourdrinier paper machine including a moving screen, a head box having a slice opening leading to said screen, a pipe through which pulp is supplied to said head box, a pressure-fluid operated regulating valve in said pipe for controlling the flow of pulp therethrough, means for regulating the opening of said valve comprising a source of pressure fluid, and means for controlling the supply of pressure fluid to said regulating valve in accordance with the height and consistency of the pulp in said head box.

I '7. In combination with a Fourdrinier paper machine including a moving screen, a head box having a slice opening leading to said screen, a pipe through which pulp is supplied to said head box, a pressure-fluid operated regulating valve in said pipe for controlling the flow of pulp therethrough, and means for regulating the opening of said valve, comprising a source of pressure fluid, and means for controlling the supply of pressure fluid to said regulating valve in accordance with the height of the pulp in said box and also in accordance with the speed of said'moving screen.

8. In combination with a Fourdrinier paper machine including a moving paper-forming screen,

ahead box provided with a slice opening leading to said screen, said head box serving to hold a pond of pulp, a pipe through which pulp is supplied to said head box, a pressure fluid operated valve in said pipe controlling the flow of pulp therethrough, and means for controlling said valve comprising a conduit connected thereto and leading to a source of pressure fluid, a pilot valve in said conduit and means for actuating said pilot valve in accordance with the height of the pulp in said pond.

9. In combination with a Fourdrinier paper machine including a moving paper-forming screen, a head box provided with a slice opening leading to said screen, said head box holding a pond of pulp, a pipe through which pulp is supplied to said head box, a pressure fluid operated valve in said pipe controlling the flow of pulp therethrough, and means for controlling said valve comprising a conduitconnectedthereto and leading to a source of pressure fluid, a pilot valve in said conduit, and means for actuating said pilot valve in accordance with the height of the pulp inwsaid pond and in'accordance'with the speed oi said moving screen. I v 1 10. In combination with a Fourdrinierpaper machine including a moving screen, a head box provided with a. slice opening leading to said screen, said head box serving to hold a pond of pulp, a pipe through which pulp is supplied to said pond, a pressure fluid actuated valve in said pipe controlling the flow of pulp therethrough, and

means for controlling said valve comprising a condult leading to a source of pressure fluid. a pilot valve controlling the flow of pressure fluid therethrough, a pressure responsive element for actuating'said pilot valve, a chamber having an open end immersed in said pond and having its other .end closed except for a conduit leading to said pressure-responsive element, and means for introducing a substantially uniform supply 0! pressure fluid to said chamber.

CLAYTON in. DE MERS. RAYMOND n. OLSON. 

